Combined with scorching temperatures and scarce rainfall, a lighted cigarette butt thrown into a small patch of roadside grass could ignite a raging brushfire.

''We need to make the people aware,'' Donohoe said. ''The flick of a cigarette or a pipe or a cigar could start a serious fire.''

Anyone who tosses a cigarette from a vehicle faces a fine of up to $500 for littering.

The state Division of Forestry has battled five brushfires in Osceola County this month. The number is not unusual, and most of the fires have been small, Donohoe said.

The largest blaze was on Monday in Poinciana, where a brushfire stretched across 55 acres and took about four hours to extinguish.

Donohoe said dry conditions have contributed to the danger of potential brushfires.

He said the month's rainfall is a scant .28 inches at the National Weather Service at Orlando International Airport. June rainfall averages 7.39 inches. Rainfall also was lower than usual in April and May, making for ''an extended dry period,'' Donohoe said.

''We're having very warm temperatures and long days. We're just sitting on the edge,'' he said.

The heat also has evaporated surface water in many of the county's swamps and wetlands.

In addition to dryness and heat, Donohoe said, lightning strikes during quick afternoon showers can spark a brushfire.

''Lightning gives us our biggest headaches because you don't know where it's going to strike,'' he said.

Lightning can spark brushfires in Osceola's remote areas and the fires may smolder for days before they are detected, Donohoe said.

Weather forecasts show only small signs of relief from the dry weather, he said.

The forecast calls for a 40 percent chance of rain today, with highs continuing in the 90's.